Method of preparing transfer copies and compositions for use therein



United States Patent 3,261,683 METHOD OF PREPARING TRANSFER COPEES AND COMPOSETIONS FOR USE THEREIN Joseph R. Sottysiak, Binghamton, John Proc, Vestal, and Charles M. Hovancik, Chenango Forks, N.Y., assignors to General Aniline 8; Film Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed May 2, 1960, Ser. No. 25,826 12 Claims. (Cl. 96-29) high density and often in effecting the transfer of the image from the exposed sensitized sheet to the receiving sheet.

It is an object of this invention to provide a diffusiontransfer process whereby a black image of high density is obtained.

It is a further object of this invention to provide a diffusion-transfer process whereby the transfer of the image is facilitated.

It is a still further object of this invention to provide a coating composition for use in forming a receiving layer on the receiving sheet in a diffusion-transfer process which composition contains bismuth nitrate.

Another object of this invention is to provide a novel receiving sheet for use in the diffusion-transfer process.

Other objects and advantages of this invention will appear to persons skilled in the art from the detailed description thereof given below.

We have discovered that by incorporating bismuth nitrate into the layer which constitutes the surface of the receiving sheet, a black image of improved density is produced by the diffusion-transfer process. Also, if a developing agent such as, for example, hydroxylamine hydrochloride, catechol, l-phenyl-Z-methyl 3 pyrazolidone or mixtures thereof, is incorporated in either the light-sensitive emulsion, the receiving sheet or the developing composition, or in all three, the transfer process is facilitated.

The light-sensitive element used in our process is of the type employed commercially. Such element comprises a base coated with a silver halide emulsion such as a silver chloride, silver bromide or the like. The emulsion may have small amounts of hydroxylamine hydrochloride added thereto. The amount of hydroxylamine hydrochloride may vary from about .2 to .8 liter of a 5% solution, preferably .5 liter per kilos of emulsion.

The solution used to coat the receiving sheet may be of the usual type to which bismuth nitrate is added as the nucleating agent. Generally, the bismuth nitrate will be employed in an amount of from .5 to 5 grams per liter of solution. Suificient nitric acid is also added to the solution to ensure that the bismuth nitrate will remain dissolved.

The transferred silver complex image is more readily formed by including in the solution hydroxylamine hydrochloride in an amount of from 10 to grams per liter. The hydroxylamine hydrochloride may be supplanted, if desired, by an equivalent amount of another reducing agent such as catechol, hydroquinone or 1-phenyl-2- methyl-3-pyrazolidone. For the rest, the solution contains the usual adjuncts such as a Water soluble colloid, i.e., gelatin, PVA, methyl cellulose or the like, an alkali metal thiocyanate, i.e., potassium thiocyanate, an alkali metal sulfite, i.e., sodium sulfite, an alkali metal thiosul- 3,261,633 Patented July 19, 1966 fate, i.e., hypo, and preferably a wetting agent such as dodecyl toluene sulfonate, lauryl sulfate or the like.

The developer used for developing the exposed lightsensitive emulsion and effecting the transfer of the silver complex contains an alkali metal sulfite, i.e., sodium sulfite, an alkali metal hydroxide, i.e., sodium hydroxide, and a photographic black and white reducing agent such as hydroxylamine hydrochloride, catechol, hydroquinone, lphenyl-2-methyl-3-pyrazolidone or the like.

The desired density in the receiving sheet can be obtained when using bismuth nitrate as the sole nucleating agent. Bismuth nitrate alone forms a black image. We prefer, however, to use with the bismuth nitrate an amount of stannous chloride since optimum results are thus achieved. If stannous chloride is used alone, it gives a brown image. When used with bismuth nitrate, an image is obtained which has optimum density. This is the reason for our preference for the combination of bismuth nitrate and stannous chloride. The stannous chloride when used will be employed in an amount of 3 to 10 grams per liter of solution.

The carrier used for both the light-sensitive layer and for the receiving layer may be either photographic paper base or clear film such as cellulose acetate or the like.

The following example illustrates our novel method. t is to be understood, however, that this example is given by way of illustration and not by way of limitation.

Example A. Negative Material.-To a silver chloride emulsion containing approximately 13 moles of silver halide per kilos was added 0.50 liter of hydroxylamine hydrochloride (5% aqueous) per 10 kilos of emulsion. This was coated on a suitable carrier such as a hotographic paper base so as to deposit 1.01.5 grams of Ag per square meter.

B. Receiving sheet.--To a 5% polyvinyl alcohol solution held in a liquid state were added per 10 liters the following materials:

I-Iydroxylamine hydrochloride grams 200 Potassium thiocyanate do 200 Sodium sulfite do 100 Sodium thiosulfate do 1.5 Bismuth nitrate (2% aqueous with sufficient nitric acid to hold in solution) cc 500 Stannous chloride (5% in methanol) do 1000 Dodecyl toluene sulfonate (10%) do 400 This was coated on a suitable carrier such as a docu ment type photographic base or a clear film base prepared to receive this coating.

The Negative Material A was exposed refiexwise to the material to be copied and then brought into intimate contact with the Receiving Sheet B in the presence of a thin layer of developer of the following formulation:

Sodium sulfite grams 66.0 Sodium hydroxide do 39.0 I-lydroxylamine hydrochloride "don" 5.0 Water cc 1000.0

After a period of 2 to 8 seconds, the two sheets were stripped apart to yield a dense image on the receiving sheet of the subject matter copied by the negative material.

Modifications of this invention will occur to persons skilled in the art. We, therefore, do not intend to be limited in the patent granted except as necessitated by the appended claims.

We claim:

1. A photographic diffusion-transfer reversal process which comprises exposing to light a photographic element having a light-sensitive emulsion layer thereon comprising silver halide and a colloid to form an. image thereon and contacting said image with a receiving layer comprising a colloid, a silver halide developing agent and bismuth nitrate in the presence of a silver halide developing solution and a silver halide solvent.

2. A photographic diffusion-transfer reversal process as recited in claim 1 wherein said receiving layer also contains stannous chloride.

3. A photographic diffusion-transfer reversal process as recited in claim 1 wherein said developing solution contains an agent selected from the group consisting of hydroxylamine hydrochloride, catechol and 1 -pheny1-2- methyl-3-pyrazolidone.

4. A photographic diffusion-transfer reversal process as recited in claim 3 wherein the developing solution contains hydroxylamine hydrochloride.

5. A photographic light-insensitive receiving element having an area suitable for receiving an image in a diffusion-transfer reversal process comprising a base and a coating on said base containing, in said image receiving area, bismuth nitrate as obtained from an aqueous solution acidified with sufiicient nitric acid to maintain said bismuth nitrate in solution.

6. A photographic receiving element as recited in claim 5 wherein said coating comprises stannous chloride.

7. A photographic light-insensitive receiving element suitable for receiving an image in a diffusion-transfer reversal process comprising a base having a coating thereon comprising a water soluble colloid, hydroxylamine hydrochloride, an alkali metal thiocyanate, an alkali metal sulfite, an alkali metal thiosulfate, bismuth nitrate and stannous chloride.

8. A photographic light-insensitive receiving element suitable for receiving an image in a diffusion-transfer reversal process comprising a base having a coating thereon comprising polyvinyl alcohol, hydroxylamine hydrochloride, potassium thiocyanate, sodium sulfite, sodium thiosulfate, bismuth nitrate, stannous chloride and the sodium salt of dodecyl toluene sulfonate.

9. A photographic receiving element as recited in claim 8 wherein the base is photographic paper.

10. A photographic light insensitive receiving element for an area suitable for receiving an image in a diffusiontransfer reversal process comprising a base and a coating on said base containing bismuth nitrate, stannous chloride and a silver halide developing agent as obtained from an aqueous solution acidified with sufficient nitric acid to maintain said bismuth nitrate in solution.

11. A photographic difiusion-transfer reversal process which comprises exposing to light underneath a pattern a light-sensitive photographic silver halide emulsion to form an image therein and contacting in the presence of a silver halide developing agent and a silver halide solvent a receiving layer comprising a colloid containing bismuth nitrate, transferring a silver salt complex to the receiving layer and nucleating said complex in said layer with said bismuth nitrate.

12. The process as defined in claim 11 wherein the hismuth nitrate is acidified with nitric acid.

References Cited by the Examiner UNITED STATES PATENTS 2,584,030 1/1952 Land 96110 X 2,686,717 8/1954 Land 9629 2,698,237 12/1954 Land 9629 2,765,240 10/1956 Land 9629 X 2,857,276 10/1958 Land et al. 9629 2,897,090 7/1959 Van Dam 9688 3,000,736 9/1961 Karlson 9629 FOREIGN PATENTS 715,196 9/1954 Great Britain. 724,001 2/1955 Great Britain.

OTHER REFERENCES Bourofl, Compt. rend, vol. 218, pages 317-18 (1944), GA. 40127425.

Land, Journal of the Optical Society of America, 37, pp. 61-77, February 1947.

NORMAN G. TORCHIN, Primary Examiner.

MILTON STERMAN, Examiner.

J. E. ALIX, G. H. BJORGE, J. T. BROWN,

Assistant Examiners. 

1. A PHOTOGRAPHIC DIFFUSION-TRANSFER REVERSAL PROCESS WHICH COMPRISES EXPOSING TO LIGHT A PHOTOGRAPHIC ELEMENT HAVING A LIGHT-SENSITIVE EMULSION LAYER THEREON COMPRISING SILVER HALIDE AND A COLLOID TO FORM AN IMAGE THEREON AND CONTACTING SAID IMAGE WITH A RECEIVING LAYER COMPRISING A COLLOID, A SILVER HALIDE DEVELOPING AGENNT AND BISMUTH NITRATE IN THE PRESENCE OF A SILVER HALIDE DEVELPING SOLUTION AND A SILVER HALIDE SOLVENT. 